There is a great debate in SEO today. It's about the nature of SEO – what it is, and what it is supposed to do.

At its basic level, SEO is simply about getting website pages listed on search engines.

At a commercial level, SEO is about hitting a specific consumer base, through the targeted use of keyword placement on search engines to promote selected pages.

There is a surprising gulf between these two – and it's polarising the industry.

The distinction is not simply one of aim, but of method.

On the one hand is something known as "Content SEO". This is a broad tool. Good content invites people to link to it. More than that, good content can catch a whole net of low traffic terms, that in number can create very significant traffic.

On the other hand, there is "Link-building" SEO. Used properly this is a precision tool, because you can use anchor text to spectacular effect to hit competitive keywords, so that the traffic from the search engines to the site is very targeted.

Hopefully, you can already see the difference. If not, here's an analogy:

Two fishermen both go to sea, both aiming to catch tuna. One of them has a big net, and simply trawls a big net around the ocean. The other fisherman has a smaller fishing net, but sails straight to the tuna fishing grounds. Which of them is most likely to be most successful in their aims?

The trouble is, sometimes the fisherman with the big net has gotten lucky. And sail back to port and reveal their triumph to all the other fishermen. So all the other fishermen go out to sea in their little boats and large nets, aimlessly trawling the oceans, figuring that they're doing good tuna fishing.

The fisherman with the smaller net might not even tell anyone about his success if he can help it. After all, why tell everyone else where the best tuna fishing can be had?

Funnily enough, when the fisherman mentions that he knows where the fishing grounds are, and that you can't catch the really big tuna without going to these places, some of the other fishermen laugh and scoff, because there's another fisherman around with a really big net who says that trawling the ocean worked for him.

The position of those fishermen should be obvious by analogy, but - surprisingly - is still seriously contested within the industry by people who became successful over the years by have trawling their big aimless nets.

Another problem is that many webmasters will rate the success of their website by their traffic numbers. That's all well and good in a non-commercial environment, but as soon as you are looking to make sales, you have to start worrying about conversion rates. And that means you aim for targeted traffic. There's little point in boasting about having one thousand unique visitors a day if your conversion rate is 0.05%, when another webmaster selling the same product has only 100 unique visitors a day but a conversion rate of 1.5%.

"Content SEO" can play a very great and significant role in an overall SEO strategy. In fact, used properly it's like sailing to the tuna grounds with an even bigger net. By itself, though, "Content SEO" is of only very limited use in a commercial environment.